The Optical/Near-Infrared Light Curves of SN 2002ap for the First 1.5 Years after Discovery
The Optical/Near-Infrared Light Curves of SN 2002ap for the First 1.5 Years after Discovery
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DOI：
10.1086/503554
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发表时间：
2003-04
期刊：
影响因子：
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通讯作者：
H. Tomita;J. Deng;K. Maeda;Y. Yoshii;K. Nomoto;P. Mazzali;Tomoharu Suzuki;Yukiyasu Kobayashi
中科院分区：
文献类型：
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作者：
H. Tomita;J. Deng;K. Maeda;Y. Yoshii;K. Nomoto;P. Mazzali;Tomoharu Suzuki;Yukiyasu Kobayashi
本文介绍了2002年6月12日至2003年8月29日期间用MAGNUM望远镜对奇特的Ic型SN 2002 ap进行的晚时BVRIJHK测光。通过与星云光谱和SN 1998 bw光谱的比较，研究了其颜色演化。利用测光方法，建立了OIR辐射热光变曲线，该曲线从光极大值前一直延伸到爆炸后580天。它的光变曲线与超新星SN 1998 bw的形状惊人地相似。下降速率从第130天和第230天之间的0.018 mag/天变化到第270天和第580天之间的0.014 mag/天。为了重现后期的光变曲线，必须在一维超新星模型中加入一个致密的核心，使其最适合早期的观测，使喷出物的质量从2.5到3 M，而动能没有太大变化，即4 × 1051尔格。这与其他超新星的情况相似，并表明不对称。在~ 300天后，谱线能量分布中出现了一个较大的H带隆起，可能是由强的[Si I] 1.646和1.608 μm辐射引起的。在第580天，近红外通量贡献从50%同时增加。与其它Ib/c型超新星的近红外光变曲线进行了比较，其中SN 1983 I与SN 2002 ap在近红外光和光学上都相似。
Late-time BVRIJHK photometry of the peculiar Type Ic SN 2002ap, taken between 2002 June 12 and 2003 August 29 with the MAGNUM Telescope, is presented. The light-curve decline rate is derived in each band, and the color evolution is studied through comparison with nebular spectra and with SN 1998bw. Using the photometry, the OIR bolometric light curve is built, extending from before light maximum to day 580 after explosion. The light curve has a late-time shape strikingly similar to that of the hypernova SN 1998bw. The decline rate changes from 0.018 mag day-1 between days 130 and 230 to 0.014 mag day-1 between days 270 and 580. To reproduce the late-time light curve, a dense core must be added to the one-dimensional hypernova model that best fits the early-time observations, bringing the ejecta mass from 2.5 to 3 M☉ without much change in the kinetic energy, which is 4 × 1051 ergs. This is similar to the case of other hypernovae and suggests asymmetry. A large H-band bump developed in the spectral energy distribution after ~day 300, probably caused by strong [Si I] 1.646 and 1.608 μm emissions. The near-infrared flux contribution increased simultaneously from 50% at day 580. The near-infrared light curves were compared with those of other Type Ib/c supernovae, among which SN 1983I seems similar to SN 2002ap both in the near-infrared and in the optical.